A conventional driving simulation device permits a player to simulate a real driving action. For instance, a motorcycle simulator includes a motorcycle-like apparatus to be driven by a rider so as to generate an operating signal that is transmitted to a processor for processing the signal in such a manner that a response thereof to the operating signal is displayed in a display device.
Referring to FIG. 1, a game device for a motorcycle simulator 60 is shown to include a driver seat 61, a coupler shaft 62 and a mounting frame 63. The driver seat 61 is fixed on the coupler shaft 62, which, in turn, is journaled to the mounting frame 63. The coupler shaft 62 extends along a rotating axis B so that, during simulating the driving operation, the rider can swing the driver seat 61 about the rotating axis B. The swinging action of the driver seat 61 is achieved by changing the gravity center of the rider's body relative to the mounting frame 63.
Since there is only a single rotating axis B in the aforesaid motorcycle simulator 60 and in case the driver seat 61 is swung to a relatively large angle during simulating a turning action, the rider must use his leg to prevent the driver seat 61 from falling to an inclined position, and such a manipulation un-stabilizes the driver seat 61. Since the entire weight of the driver seat 61 and the rider is sustained by the coupler shaft 62, the motorcycle simulator 60 is susceptible to damage easily. In case the driver seat 61 is at an inclined position, the rider must apply a tremendously large force to erect the driver seat 61 back to its normal position from the inclined position, since the rotating axis B is located below the driver seat 61. Moreover, due that there is no position restoration mechanism to assist the driver seat 61 to retrieve its initial position, the rider must use his/her body to maintain the desired stability of the driver seat 61, and such a move discomforts the rider.